<?php
namespace Grav\Plugin\Admin;

use DateTime;
use Grav\Common\Data;
use Grav\Common\File\CompiledYamlFile;
use Grav\Common\GPM\GPM;
use Grav\Common\GPM\Licenses;
use Grav\Common\GPM\Response;
use Grav\Common\Grav;
use Grav\Common\Language\LanguageCodes;
use Grav\Common\Page\Page;
use Grav\Common\Page\Pages;
use Grav\Common\Plugins;
use Grav\Common\Themes;
use Grav\Common\Uri;
use Grav\Common\User\User;
use Grav\Common\Utils;
use Grav\Plugin\Admin\Utils as AdminUtils;
use RocketTheme\Toolbox\Event\Event;
use RocketTheme\Toolbox\File\File;
use RocketTheme\Toolbox\File\JsonFile;
use RocketTheme\Toolbox\ResourceLocator\UniformResourceIterator;
use RocketTheme\Toolbox\ResourceLocator\UniformResourceLocator;
use RocketTheme\Toolbox\Session\Message;
use RocketTheme\Toolbox\Session\Session;
use Symfony\Component\Yaml\Yaml;
use Composer\Semver\Semver;
use PicoFeed\Reader\Reader;
use RobThree\Auth\TwoFactorAuth;

define('LOGIN_REDIRECT_COOKIE', 'grav-login-redirect');

class Admin
{
    const MEDIA_PAGINATION_INTERVAL = 20;
    const TMP_COOKIE_NAME = 'tmp-admin-message';

    /**
     * @var Grav
     */
    public $grav;
    /**
     * @var string
     */
    public $base;
    /**
     * @var string
     */
    public $location;
    /**
     * @var string
     */
    public $route;
    /**
     * @var User
     */
    public $user;
    /**
     * @var array
     */
    public $forgot;
    /**
     * @var string
     */
    public $task;
    /**
     * @var array
     */
    public $json_response;
    /**
     * @var Uri $uri
     */
    protected $uri;
    /**
     * @var array
     */
    protected $pages = [];
    /**
     * @var Session
     */
    protected $session;
    /**
     * @var Data\Blueprints
     */
    protected $blueprints;
    /**
     * @var GPM
     */
    protected $gpm;

    /**
     * @var int
     */
    protected $pages_count;

    /**
     * @var array
     */
    protected $permissions;

    /**
     * @var bool
     */
    protected $load_additional_files_in_background = false;

    /**
     * @var bool
     */
    protected $loading_additional_files_in_background = false;

    /**
     * @var array
     */
    protected $temp_messages = [];

    /**
     * Constructor.
     *
     * @param Grav   $grav
     * @param string $base
     * @param string $location
     * @param string $route
     */
    public function __construct(Grav $grav, $base, $location, $route)
    {
        $this->grav        = $grav;
        $this->base        = $base;
        $this->location    = $location;
        $this->route       = $route;
        $this->uri         = $this->grav['uri'];
        $this->session     = $this->grav['session'];
        $this->user        = $this->grav['user'];
        $this->permissions = [];
        $language          = $this->grav['language'];

        // Load utility class
        if ($language->enabled()) {
            $this->multilang         = true;
            $this->languages_enabled = $this->grav['config']->get('system.languages.supported', []);

            //Set the currently active language for the admin
            $language = $this->grav['uri']->param('lang');
            if (!$language) {
                if (!$this->session->admin_lang) {
                    $this->session->admin_lang = $this->grav['language']->getLanguage();
                }
                $language = $this->session->admin_lang;
            }
            $this->grav['language']->setActive($language ?: 'en');
        } else {
            $this->grav['language']->setActive('en');
            $this->multilang = false;
        }

    }

    /**
     * Return the languages available in the admin
     *
     * @return array
     */
    public static function adminLanguages()
    {
        $languages = [];

        $path = Grav::instance()['locator']->findResource('plugins://admin/languages');

        /** @var \DirectoryIterator $directory */
        foreach (new \DirectoryIterator($path) as $file) {
            if ($file->isDir() || $file->isDot() || Utils::startsWith($file->getBasename(), '.')) {
                continue;
            }

            $lang = basename($file->getBasename(), '.yaml');

            $languages[$lang] = LanguageCodes::getNativeName($lang);

        }

        return $languages;
    }

    /**
     * Return the found configuration blueprints
     *
     * @return array
     */
    public static function configurations()
    {
        $configurations = [];

        /** @var UniformResourceIterator $iterator */
        $iterator = Grav::instance()['locator']->getIterator('blueprints://config');

        foreach ($iterator as $file) {
            if ($file->isDir() || !preg_match('/^[^.].*.yaml$/', $file->getFilename())) {
                continue;
            }
            $configurations[] = basename($file->getBasename(), '.yaml');
        }

        return $configurations;
    }

    /**
     * Return the tools found
     *
     * @return array
     */
    public static function tools()
    {
        $tools = [];
        $event = Grav::instance()->fireEvent('onAdminTools', new Event(['tools' => &$tools]));

        return $tools;
    }

    /**
     * Return the languages available in the site
     *
     * @return array
     */
    public static function siteLanguages()
    {
        $languages = [];
        $lang_data = Grav::instance()['config']->get('system.languages.supported', []);

        foreach ($lang_data as $index => $lang) {
            $languages[$lang] = LanguageCodes::getNativeName($lang);
        }

        return $languages;
    }

    /**
     * Static helper method to return the admin form nonce
     *
     * @return string
     */
    public static function getNonce()
    {
        $action = 'admin-form';

        return Utils::getNonce($action);
    }

    /**
     * Static helper method to return the last used page name
     *
     * @return string
     */
    public static function getLastPageName()
    {
        return Grav::instance()['session']->lastPageName ?: 'default';
    }

    /**
     * Static helper method to return the last used page route
     *
     * @return string
     */
    public static function getLastPageRoute()
    {
        return Grav::instance()['session']->lastPageRoute ?: self::route();
    }

    /**
     * Static helper method to return current route.
     *
     * @return string
     */
    public static function route()
    {
        $pages = Grav::instance()['pages'];
        $route = '/' . ltrim(Grav::instance()['admin']->route, '/');

        /** @var Page $page */
        $page         = $pages->dispatch($route);
        $parent_route = null;
        if ($page) {
            $parent       = $page->parent();
            $parent_route = $parent->rawRoute();
        }

        return $parent_route;
    }

    public static function getTempDir()
    {
        try {
            $tmp_dir = Grav::instance()['locator']->findResource('tmp://', true, true);
        } catch (\Exception $e) {
            $tmp_dir = Grav::instance()['locator']->findResource('cache://', true, true) . '/tmp';
        }

        return $tmp_dir;
    }

    public static function getPageMedia()
    {
        $files = [];
        $grav = Grav::instance();

        $pages = $grav['pages'];
        $route = '/' . ltrim($grav['admin']->route, '/');

        /** @var Page $page */
        $page         = $pages->dispatch($route);
        $parent_route = null;
        if ($page) {
            $media = $page->media()->all();
            $files = array_keys($media);
        }
        return $files;

    }

    /**
     * Get current session.
     *
     * @return Session
     */
    public function session()
    {
        return $this->session;
    }

    /**
     * Fetch and delete messages from the session queue.
     *
     * @param string $type
     *
     * @return array
     */
    public function messages($type = null)
    {
        /** @var Message $messages */
        $messages = $this->grav['messages'];

        return $messages->fetch($type);
    }

    /**
     * Authenticate user.
     *
     * @param  array $data Form data.
     * @param  array $post Additional form fields.
     *
     * @return bool
     */
    public function authenticate($data, $post)
    {
        $count = $this->grav['config']->get('plugins.login.max_login_count', 5);
        $interval = $this->grav['config']->get('plugins.login.max_login_interval', 10);
        $login = $this->grav['login'];

        if ($login->isUserRateLimited($this->user, 'login_attempts', $count, $interval)) {
            $this->setMessage($this->translate(['PLUGIN_LOGIN.TOO_MANY_LOGIN_ATTEMPTS', $interval]), 'error');
            $this->grav->redirect($post['redirect']);
            return true;
        }


        if (!$this->user->authenticated && isset($data['username']) && isset($data['password'])) {
            // Perform RegEX check on submitted username to check for emails
            if (filter_var($data['username'], FILTER_VALIDATE_EMAIL)) {
                $user = AdminUtils::findUserByEmail($data['username']);
            } else {
                $user = User::load($data['username']);
            }

            //default to english if language not set
            if (empty($user->language)) {
                $user->set('language', 'en');
            }

            if ($user->exists()) {

                // Authenticate user.
                $result = $user->authenticate($data['password']);

                if (!$result) {
                    return false;
                }
            }
        }


        $twofa_admin_enabled = $this->grav['config']->get('plugins.admin.twofa_enabled', false);
        if ($twofa_admin_enabled && isset($user->twofa_enabled) &&
            $user->twofa_enabled == true && !$user->authenticated) {
            $this->session->redirect = $post['redirect'];
            $this->session->user = $user;

            $this->grav->redirect($this->base . '/twofa');
        }

        $user->authenticated = true;
        $login->resetRateLimit($user,'login_attempts');

        if ($user->authorize('admin.login')) {
            $this->user = $this->session->user = $user;

            /** @var Grav $grav */
            $grav = $this->grav;

            unset($this->grav['user']);
            $this->grav['user'] = $user;

            $this->setMessage($this->translate('PLUGIN_ADMIN.LOGIN_LOGGED_IN'), 'info');
            $grav->redirect($post['redirect']);

            return true; //never reached
        }

        return false;
    }

    /**
     * Add message into the session queue.
     *
     * @param string $msg
     * @param string $type
     */
    public function setMessage($msg, $type = 'info')
    {
        /** @var Message $messages */
        $messages = $this->grav['messages'];
        $messages->add($msg, $type);
    }

    public function addTempMessage($msg, $type)
    {
        $this->temp_messages[] = ['message' => $msg, 'scope' => $type];
    }

    public function getTempMessages()
    {
        return $this->temp_messages;
    }

    /**
     * Translate a string to the user-defined language
     *
     * @param array|mixed $args
     *
     * @param mixed       $languages
     *
     * @return string
     */
    public static function translate($args, $languages = null)
    {
        $grav = Grav::instance();

        if (is_array($args)) {
            $lookup = array_shift($args);
        } else {
            $lookup = $args;
            $args   = [];
        }

        if (!$languages) {
            $languages = [$grav['user']->authenticated ? $grav['user']->language : 'en'];
        } else {
            $languages = (array)$languages;
        }

        if ($lookup) {
            if (empty($languages) || reset($languages) == null) {
                if ($grav['config']->get('system.languages.translations_fallback', true)) {
                    $languages = $grav['language']->getFallbackLanguages();
                } else {
                    $languages = (array)$grav['language']->getDefault();
                }
            }
        }

        foreach ((array)$languages as $lang) {
            $translation = $grav['language']->getTranslation($lang, $lookup);

            if (!$translation) {
                $language    = $grav['language']->getDefault() ?: 'en';
                $translation = $grav['language']->getTranslation($language, $lookup);
            }

            if (!$translation) {
                $language    = 'en';
                $translation = $grav['language']->getTranslation($language, $lookup);
            }

            if ($translation) {
                if (count($args) >= 1) {
                    return vsprintf($translation, $args);
                } else {
                    return $translation;
                }
            }
        }

        return $lookup;
    }

    /**
     * Checks user authorisation to the action.
     *
     * @param  string $action
     *
     * @return bool
     */
    public function authorize($action = 'admin.login')
    {
        $action = (array)$action;

        foreach ($action as $a) {
            if ($this->user->authorize($a)) {
                return true;
            }
        }

        return false;
    }

    /**
     * Gets configuration data.
     *
     * @param string $type
     * @param array  $post
     *
     * @return mixed
     * @throws \RuntimeException
     */
    public function data($type, array $post = [])
    {
        static $data = [];

        if (isset($data[$type])) {
            return $data[$type];
        }

        if (!$post) {
            $post = isset($_POST['data']) ? $_POST['data'] : [];
        }

        // Check to see if a data type is plugin-provided, before looking into core ones
        $event = $this->grav->fireEvent('onAdminData', new Event(['type' => &$type]));
        if ($event && isset($event['data_type'])) {
            return $event['data_type'];
        }

        /** @var UniformResourceLocator $locator */
        $locator  = $this->grav['locator'];
        $filename = $locator->findResource("config://{$type}.yaml", true, true);
        $file     = CompiledYamlFile::instance($filename);

        if (preg_match('|plugins/|', $type)) {
            /** @var Plugins $plugins */
            $plugins = $this->grav['plugins'];
            $obj     = $plugins->get(preg_replace('|plugins/|', '', $type));

            if (!$obj) {
                return [];
            }

            $obj->merge($post);
            $obj->file($file);

            $data[$type] = $obj;
        } elseif (preg_match('|themes/|', $type)) {
            /** @var Themes $themes */
            $themes = $this->grav['themes'];
            $obj    = $themes->get(preg_replace('|themes/|', '', $type));

            if (!$obj) {
                return [];
            }

            $obj->merge($post);
            $obj->file($file);

            $data[$type] = $obj;
        } elseif (preg_match('|users/|', $type)) {
            $obj = User::load(preg_replace('|users/|', '', $type));
            $obj->merge($post);

            $data[$type] = $obj;
        } elseif (preg_match('|user/|', $type)) {
            $obj = User::load(preg_replace('|user/|', '', $type));
            $obj->merge($post);

            $data[$type] = $obj;
        } elseif (preg_match('|config/|', $type)) {
            $type       = preg_replace('|config/|', '', $type);
            $blueprints = $this->blueprints("config/{$type}");
            $config     = $this->grav['config'];
            $obj        = new Data\Data($config->get($type, []), $blueprints);
            $obj->merge($post);

            // FIXME: We shouldn't allow user to change configuration files in system folder!
            $filename = $this->grav['locator']->findResource("config://{$type}.yaml")
                ?: $this->grav['locator']->findResource("config://{$type}.yaml", true, true);
            $file     = CompiledYamlFile::instance($filename);
            $obj->file($file);
            $data[$type] = $obj;
        } elseif (preg_match('|media-manager/|', $type)) {
            $filename = base64_decode(preg_replace('|media-manager/|', '', $type));

            $file = File::instance($filename);

            $obj = new \StdClass();
            $obj->title = $file->basename();
            $obj->path = $file->filename();
            $obj->file = $file;
            $obj->page = $this->grav['pages']->get(dirname($obj->path));

            $filename = pathinfo($obj->title)['filename'];
            $filename = str_replace(['@3x', '@2x'], '', $filename);
            if (isset(pathinfo($obj->title)['extension'])) {
                $filename .= '.' . pathinfo($obj->title)['extension'];
            }

            if ($obj->page && isset($obj->page->media()[$filename])) {
                $obj->metadata = new Data\Data($obj->page->media()[$filename]->metadata());
            }

            $data[$type] = $obj;
        } else {
            throw new \RuntimeException("Data type '{$type}' doesn't exist!");
        }

        return $data[$type];
    }

    protected function hasErrorMessage()
    {
        $msgs = $this->grav['messages']->all();
        foreach ($msgs as $msg) {
            if (isset($msg['scope']) && $msg['scope'] === 'error') {
                return true;
            }
        }
        return false;
    }

    /**
     * Returns blueprints for the given type.
     *
     * @param string $type
     *
     * @return Data\Blueprint
     */
    public function blueprints($type)
    {
        if ($this->blueprints === null) {
            $this->blueprints = new Data\Blueprints('blueprints://');
        }

        return $this->blueprints->get($type);
    }

    /**
     * Converts dot notation to array notation.
     *
     * @param  string $name
     *
     * @return string
     */
    public function field($name)
    {
        $path = explode('.', $name);

        return array_shift($path) . ($path ? '[' . implode('][', $path) . ']' : '');
    }

    /**
     * Get all routes.
     *
     * @param bool $unique
     *
     * @return array
     */
    public function routes($unique = false)
    {
        /** @var Pages $pages */
        $pages = $this->grav['pages'];

        if ($unique) {
            $routes = array_unique($pages->routes());
        } else {
            $routes = $pages->routes();
        }

        return $routes;
    }

    /**
     * Count the pages
     *
     * @return array
     */
    public function pagesCount()
    {
        if (!$this->pages_count) {
            $this->pages_count = count($this->grav['pages']->all());
        }

        return $this->pages_count;
    }

    /**
     * Get all template types
     *
     * @return array
     */
    public function types()
    {
        return Pages::types();
    }

    /**
     * Get all modular template types
     *
     * @return array
     */
    public function modularTypes()
    {
        return Pages::modularTypes();
    }

    /**
     * Get all access levels
     *
     * @return array
     */
    public function accessLevels()
    {
        if (method_exists($this->grav['pages'], 'accessLevels')) {
            return $this->grav['pages']->accessLevels();
        } else {
            return [];
        }
    }

    public function license($package_slug)
    {
        return Licenses::get($package_slug);
    }

    /**
     * Generate an array of dependencies for a package, used to generate a list of
     * packages that can be removed when removing a package.
     *
     * @param string $slug The package slug
     *
     * @return array|bool
     */
    public function dependenciesThatCanBeRemovedWhenRemoving($slug)
    {
        $gpm = $this->gpm();
        if (!$gpm) {
            return false;
        }

        $dependencies = [];

        $package = $this->getPackageFromGPM($slug);

        if ($package) {
            if ($package->dependencies) {
                foreach ($package->dependencies as $dependency) {
                    if (count($gpm->getPackagesThatDependOnPackage($dependency)) > 1) {
                        continue;
                    }

                    if (!in_array($dependency, $dependencies)) {
                        if (!in_array($dependency, ['admin', 'form', 'login', 'email'])) {
                            $dependencies[] = $dependency;
                        }
                    }
                }
            }
        }

        return $dependencies;
    }

    /**
     * Get the GPM instance
     *
     * @return GPM The GPM instance
     */
    public function gpm()
    {
        if (!$this->gpm) {
            try {
                $this->gpm = new GPM();
            } catch (\Exception $e) {
            }
        }

        return $this->gpm;
    }

    public function getPackageFromGPM($package_slug)
    {
        $package = $this->plugins(true)[$package_slug];
        if (!$package) {
            $package = $this->themes(true)[$package_slug];
        }

        return $package;
    }

    /**
     * Get all plugins.
     *
     * @param bool $local
     *
     * @return mixed
     */
    public function plugins($local = true)
    {
        $gpm = $this->gpm();

        if (!$gpm) {
            return false;
        }

        if ($local) {
            return $gpm->getInstalledPlugins();
        } else {
            $plugins = $gpm->getRepositoryPlugins();
            if ($plugins) {
                return $plugins->filter(function (
                    $package,
                    $slug
                ) use ($gpm) {
                    return !$gpm->isPluginInstalled($slug);
                });
            } else {
                return [];
            }
        }
    }

    /**
     * Get all themes.
     *
     * @param bool $local
     *
     * @return mixed
     */
    public function themes($local = true)
    {
        $gpm = $this->gpm();

        if (!$gpm) {
            return false;
        }

        if ($local) {
            return $gpm->getInstalledThemes();
        } else {
            $themes = $gpm->getRepositoryThemes();
            if ($themes) {
                return $themes->filter(function (
                    $package,
                    $slug
                ) use ($gpm) {
                    return !$gpm->isThemeInstalled($slug);
                });
            } else {
                return [];
            }
        }
    }

    /**
     * Get list of packages that depend on the passed package slug
     *
     * @param string $slug The package slug
     *
     * @return array|bool
     */
    public function getPackagesThatDependOnPackage($slug)
    {
        $gpm = $this->gpm();
        if (!$gpm) {
            return false;
        }

        return $gpm->getPackagesThatDependOnPackage($slug);
    }

    /**
     * Check the passed packages list can be updated
     *
     * @param $packages
     *
     * @throws \Exception
     * @return bool
     */
    public function checkPackagesCanBeInstalled($packages)
    {
        $gpm = $this->gpm();
        if (!$gpm) {
            return false;
        }

        $this->gpm->checkPackagesCanBeInstalled($packages);

        return true;
    }

    /**
     * Get an array of dependencies needed to be installed or updated for a list of packages
     * to be installed.
     *
     * @param array $packages The packages slugs
     *
     * @return array|bool
     */
    public function getDependenciesNeededToInstall($packages)
    {
        $gpm = $this->gpm();
        if (!$gpm) {
            return false;
        }

        $dependencies = $this->gpm->getDependencies($packages);

        return $dependencies;
    }

    /**
     * Used by the Dashboard in the admin to display the X latest pages
     * that have been modified
     *
     * @param  integer $count number of pages to pull back
     *
     * @return array|null
     */
    public function latestPages($count = 10)
    {
        /** @var Pages $pages */
        $pages = $this->grav['pages'];

        $latest = [];

        if (is_null($pages->routes())) {
            return null;
        }

        foreach ($pages->routes() as $url => $path) {
            $page = $pages->dispatch($url, true);
            if ($page && $page->routable()) {
                $latest[$page->route()] = ['modified' => $page->modified(), 'page' => $page];
            }
        }

        // sort based on modified
        uasort($latest, function ($a, $b) {
            if ($a['modified'] == $b['modified']) {
                return 0;
            }

            return ($a['modified'] > $b['modified']) ? -1 : 1;
        });

        // build new array with just pages in it
        $list = [];
        foreach ($latest as $item) {
            $list[] = $item['page'];
        }

        return array_slice($list, 0, $count);
    }

    /**
     * Get log file for fatal errors.
     *
     * @return string
     */
    public function logEntry()
    {
        $file    = File::instance($this->grav['locator']->findResource("log://{$this->route}.html"));
        $content = $file->content();

        return $content;
    }

    /**
     * Search in the logs when was the latest backup made
     *
     * @return array Array containing the latest backup information
     */
    public function lastBackup()
    {
        $file    = JsonFile::instance($this->grav['locator']->findResource("log://backup.log"));
        $content = $file->content();
        if (empty($content)) {
            return [
                'days'        => '&infin;',
                'chart_fill'  => 100,
                'chart_empty' => 0
            ];
        }

        $backup = new \DateTime();
        $backup->setTimestamp($content['time']);
        $diff = $backup->diff(new \DateTime());

        $days       = $diff->days;
        $chart_fill = $days > 30 ? 100 : round($days / 30 * 100);

        return [
            'days'        => $days,
            'chart_fill'  => $chart_fill,
            'chart_empty' => 100 - $chart_fill
        ];
    }

    /**
     * Determine if the plugin or theme info passed is from Team Grav
     *
     * @param object $info Plugin or Theme info object
     *
     * @return bool
     */
    public function isTeamGrav($info)
    {
        if (isset($info['author']['name']) && ($info['author']['name'] == 'Team Grav' || Utils::contains($info['author']['name'], 'Trilby Media'))) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * Determine if the plugin or theme info passed is premium
     *
     * @param object $info Plugin or Theme info object
     *
     * @return bool
     */
    public function isPremiumProduct($info)
    {
        if (isset($info['premium'])) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * Renders phpinfo
     *
     * @return string The phpinfo() output
     */
    function phpinfo()
    {
        if (function_exists('phpinfo')) {
            ob_start();
            phpinfo();
            $pinfo = ob_get_contents();
            ob_end_clean();

            $pinfo = preg_replace('%^.*<body>(.*)</body>.*$%ms', '$1', $pinfo);

            return $pinfo;
        } else {
            return 'phpinfo() method is not available on this server.';
        }
    }

    /**
     * Guest date format based on euro/US
     *
     * @param $date
     *
     * @return string
     */
    public function guessDateFormat($date)
    {
        static $guess;

        $date_formats = [
            'm/d/y',
            'm/d/Y',
            'n/d/y',
            'n/d/Y',
            'd-m-Y',
            'd-m-y',
        ];

        $time_formats = [
            'H:i',
            'G:i',
            'h:ia',
            'g:ia'
        ];

        if (!isset($guess[$date])) {
            foreach ($date_formats as $date_format) {
                foreach ($time_formats as $time_format) {
                    if ($this->validateDate($date, "$date_format $time_format")) {
                        $guess[$date] = "$date_format $time_format";
                        break 2;
                    } elseif ($this->validateDate($date, "$time_format $date_format")) {
                        $guess[$date] = "$time_format $date_format";
                        break 2;
                    }
                }
            }

            if (!isset($guess[$date])) {
                $guess[$date] = 'd-m-Y H:i';
            }
        }

        return $guess[$date];
    }

    public function validateDate($date, $format)
    {
        $d = DateTime::createFromFormat($format, $date);

        return $d && $d->format($format) == $date;
    }

    /**
     * @param string $php_format
     *
     * @return string
     */
    public function dateformatToMomentJS($php_format)
    {
        $SYMBOLS_MATCHING = [
            // Day
            'd' => 'DD',
            'D' => 'ddd',
            'j' => 'D',
            'l' => 'dddd',
            'N' => 'E',
            'S' => 'Do',
            'w' => 'd',
            'z' => 'DDD',
            // Week
            'W' => 'W',
            // Month
            'F' => 'MMMM',
            'm' => 'MM',
            'M' => 'MMM',
            'n' => 'M',
            't' => '',
            // Year
            'L' => '',
            'o' => 'GGGG',
            'Y' => 'YYYY',
            'y' => 'yy',
            // Time
            'a' => 'a',
            'A' => 'A',
            'B' => 'SSS',
            'g' => 'h',
            'G' => 'H',
            'h' => 'hh',
            'H' => 'HH',
            'i' => 'mm',
            's' => 'ss',
            'u' => '',
            // Timezone
            'e' => '',
            'I' => '',
            'O' => 'ZZ',
            'P' => 'Z',
            'T' => 'z',
            'Z' => '',
            // Full Date/Time
            'c' => '',
            'r' => 'llll ZZ',
            'U' => 'X'
        ];
        $js_format        = "";
        $escaping         = false;
        for ($i = 0; $i < strlen($php_format); $i++) {
            $char = $php_format[$i];
            if ($char === '\\') // PHP date format escaping character
            {
                $i++;
                if ($escaping) {
                    $js_format .= $php_format[$i];
                } else {
                    $js_format .= '\'' . $php_format[$i];
                }
                $escaping = true;
            } else {
                if ($escaping) {
                    $js_format .= "'";
                    $escaping = false;
                }
                if (isset($SYMBOLS_MATCHING[$char])) {
                    $js_format .= $SYMBOLS_MATCHING[$char];
                } else {
                    $js_format .= $char;
                }
            }
        }

        return $js_format;
    }

    /**
     * Gets the entire permissions array
     *
     * @return array
     */
    public function getPermissions()
    {
        return $this->permissions;
    }

    /**
     * Sets the entire permissions array
     *
     * @param $permissions
     */
    public function setPermissions($permissions)
    {
        $this->permissions = $permissions;
    }

    /**
     * Adds a permission to the permissions array
     *
     * @param $permissions
     */
    public function addPermissions($permissions)
    {
        $this->permissions = array_merge($this->permissions, $permissions);
    }

    public function processNotifications($notifications)
    {
        // Sort by date
        usort($notifications, function ($a, $b) {
            return strcmp($a->date, $b->date);
        });

        $notifications = array_reverse($notifications);

        // Make adminNicetimeFilter available
        require_once(__DIR__ . '/../twig/AdminTwigExtension.php');
        $adminTwigExtension = new AdminTwigExtension();

        $filename           = $this->grav['locator']->findResource('user://data/notifications/' . $this->grav['user']->username . YAML_EXT,
            true, true);
        $read_notifications = CompiledYamlFile::instance($filename)->content();

        $notifications_processed = [];
        foreach ($notifications as $key => $notification) {
            $is_valid = true;

            if (in_array($notification->id, $read_notifications)) {
                $notification->read = true;
            }

            if ($is_valid && isset($notification->permissions) && !$this->authorize($notification->permissions)) {
                $is_valid = false;
            }

            if ($is_valid && isset($notification->dependencies)) {
                foreach ($notification->dependencies as $dependency => $constraints) {
                    if ($dependency == 'grav') {
                        if (!Semver::satisfies(GRAV_VERSION, $constraints)) {
                            $is_valid = false;
                        }
                    } else {
                        $packages = array_merge($this->plugins()->toArray(), $this->themes()->toArray());
                        if (!isset($packages[$dependency])) {
                            $is_valid = false;
                        } else {
                            $version = $packages[$dependency]['version'];
                            if (!Semver::satisfies($version, $constraints)) {
                                $is_valid = false;
                            }
                        }
                    }

                    if (!$is_valid) {
                        break;
                    }
                }
            }

            if ($is_valid) {
                $notifications_processed[] = $notification;
            }
        }

        // Process notifications
        $notifications_processed = array_map(function ($notification) use ($adminTwigExtension) {
            $notification->date = $adminTwigExtension->adminNicetimeFilter($notification->date);

            return $notification;
        }, $notifications_processed);

        return $notifications_processed;
    }

    public function findFormFields($type, $fields, $found_fields = [])
    {
        foreach ($fields as $key => $field) {

            if (isset($field['type']) && $field['type'] == $type) {
                $found_fields[$key] = $field;
            } elseif (isset($field['fields'])) {
                $result = $this->findFormFields($type, $field['fields'], $found_fields);
                if (!empty($result)) {
                    $found_fields = array_merge($found_fields, $result);
                }
            }
        }

        return $found_fields;
    }

    public function getPagePathFromToken($path)
    {
        return Utils::getPagePathFromToken($path, $this->page(true));
    }

    /**
     * Returns edited page.
     *
     * @param bool $route
     *
     * @param null $path
     *
     * @return Page
     */
    public function page($route = false, $path = null)
    {
        if (!$path) {
            $path = $this->route;
        }

        if ($route && !$path) {
            $path = '/';
        }

        if (!isset($this->pages[$path])) {
            $this->pages[$path] = $this->getPage($path);
        }

        return $this->pages[$path];
    }

    /**
     * Returns the page creating it if it does not exist.
     *
     * @param $path
     *
     * @return Page
     */
    public function getPage($path)
    {
        /** @var Pages $pages */
        $pages = $this->grav['pages'];

        if ($path && $path[0] != '/') {
            $path = "/{$path}";
        }

        $page = $path ? $pages->dispatch($path, true) : $pages->root();

        if (!$page) {
            $slug = basename($path);

            if ($slug == '') {
                return null;
            }

            $ppath = str_replace('\\', '/', dirname($path));

            // Find or create parent(s).
            $parent = $this->getPage($ppath != '/' ? $ppath : '');

            // Create page.
            $page = new Page;
            $page->parent($parent);
            $page->filePath($parent->path() . '/' . $slug . '/' . $page->name());

            // Add routing information.
            $pages->addPage($page, $path);

            // Set if Modular
            $page->modularTwig($slug[0] == '_');

            // Determine page type.
            if (isset($this->session->{$page->route()})) {
                // Found the type and header from the session.
                $data = $this->session->{$page->route()};

                // Set the key header value
                $header = ['title' => $data['title']];

                if (isset($data['visible'])) {
                    if ($data['visible'] == '' || $data['visible']) {
                        // if auto (ie '')
                        $children = $page->parent()->children();
                        foreach ($children as $child) {
                            if ($child->order()) {
                                // set page order
                                $page->order(AdminController::getNextOrderInFolder($page->parent()->path()));
                                break;
                            }
                        }
                    }
                    if ($data['visible'] == 1 && !$page->order()) {
                        $header['visible'] = $data['visible'];
                    }

                }

                if ($data['name'] == 'modular') {
                    $header['body_classes'] = 'modular';
                }

                $name = $page->modular() ? str_replace('modular/', '', $data['name']) : $data['name'];
                $page->name($name . '.md');

                // Fire new event to allow plugins to manipulate page frontmatter
                $this->grav->fireEvent('onAdminCreatePageFrontmatter', new Event(['header' => &$header,
                        'data' => $data]));

                $page->header($header);
                $page->frontmatter(Yaml::dump((array)$page->header(), 10, 2, false));
            } else {
                // Find out the type by looking at the parent.
                $type = $parent->childType()
                    ? $parent->childType()
                    : $parent->blueprints()->get('child_type',
                        'default');
                $page->name($type . CONTENT_EXT);
                $page->header();
            }
            $page->modularTwig($slug[0] == '_');
        }

        return $page;
    }

    /**
     * Get https://getgrav.org news feed
     *
     * @return mixed
     */
    public function getFeed()
    {
        $feed_url = 'https://getgrav.org/blog.atom';

        $body = Response::get($feed_url);

        $reader = new Reader();
        $parser = $reader->getParser($feed_url, $body, 'utf-8');

        $feed = $parser->execute();

        return $feed;

    }

    public function getRouteDetails()
    {
        return [$this->base, $this->location, $this->route];
    }

    /**
     * Get the files list
     *
     * @todo allow pagination
     * @return array
     */
    public function files($filtered = true, $page_index = 0)
    {
        $param_type = $this->grav['uri']->param('type');
        $param_date = $this->grav['uri']->param('date');
        $param_page = $this->grav['uri']->param('page');
        $param_page = str_replace('\\', '/', $param_page);

        $files_cache_key = 'media-manager-files';

        if ($param_type) {
            $files_cache_key .= "-{$param_type}";
        }
        if ($param_date) {
            $files_cache_key .= "-{$param_date}";
        }
        if ($param_page) {
            $files_cache_key .= "-{$param_page}";
        }

        $page_files = null;

        $cache_enabled = $this->grav['config']->get('plugins.admin.cache_enabled');
        if (!$cache_enabled) {
            $this->grav['cache']->setEnabled(true);
        }

        $page_files = $this->grav['cache']->fetch(md5($files_cache_key));

        if (!$cache_enabled) {
            $this->grav['cache']->setEnabled(false);
        }

        if (!$page_files) {
            $page_files = [];
            $pages = $this->grav['pages'];

            if ($param_page) {
                $page = $pages->dispatch($param_page);

                $page_files = $this->getFiles('images', $page, $page_files, $filtered);
                $page_files = $this->getFiles('videos', $page, $page_files, $filtered);
                $page_files = $this->getFiles('audios', $page, $page_files, $filtered);
                $page_files = $this->getFiles('files', $page, $page_files, $filtered);
            } else {
                $allPages = $pages->all();

                if ($allPages) foreach ($allPages as $page) {
                    $page_files = $this->getFiles('images', $page, $page_files, $filtered);
                    $page_files = $this->getFiles('videos', $page, $page_files, $filtered);
                    $page_files = $this->getFiles('audios', $page, $page_files, $filtered);
                    $page_files = $this->getFiles('files', $page, $page_files, $filtered);
                }
            }

            if (count($page_files) >= self::MEDIA_PAGINATION_INTERVAL) {
                $this->shouldLoadAdditionalFilesInBackground(true);
            }

            if (!$cache_enabled) {
                $this->grav['cache']->setEnabled(true);
            }
            $this->grav['cache']->save(md5($files_cache_key), $page_files, 600); //cache for 10 minutes
            if (!$cache_enabled) {
                $this->grav['cache']->setEnabled(false);
            }

        }

        if (count($page_files) >= self::MEDIA_PAGINATION_INTERVAL) {
            $page_files = array_slice($page_files, $page_index * self::MEDIA_PAGINATION_INTERVAL, self::MEDIA_PAGINATION_INTERVAL);
        }

        return $page_files;
    }

    public function shouldLoadAdditionalFilesInBackground($status = null)
    {
        if ($status) {
            $this->load_additional_files_in_background = true;
        }

        return $this->load_additional_files_in_background;
    }

    public function loadAdditionalFilesInBackground($status = null)
    {
        if (!$this->loading_additional_files_in_background) {
            $this->loading_additional_files_in_background = true;
            $this->files(false, false);
            $this->shouldLoadAdditionalFilesInBackground(false);
            $this->loading_additional_files_in_background = false;
        }
    }

    private function getFiles($type, $page, $page_files, $filtered)
    {
        $page_files = $this->getMediaOfType($type, $page, $page_files);

        if ($filtered) {
            $page_files = $this->filterByType($page_files);
            $page_files = $this->filterByDate($page_files);
        }

        return $page_files;
    }

    /**
     * Get all the media of a type ('images' | 'audios' | 'videos' | 'files')
     *
     * @param string $type
     * @param Page\Page $page
     * @param array $files
     *
     * @return array
     */
    private function getMediaOfType($type, $page, $page_files) {
        if ($page) {

//            $path = $page->path();
            $media = $page->media();
            $mediaOfType = $media->$type();

            foreach($mediaOfType as $title => $file) {
                $page_files[] = [
                    'title' => $title,
                    'type' => $type,
                    'page_route' => $page->route(),
                    'file' => $file->higherQualityAlternative()
                ];
            }

            return $page_files;
        } else {
            return [];
        }
    }

    /**
     * Filter media by type
     *
     * @param array $filesFiltered
     *
     * @return array
     */
    private function filterByType($filesFiltered)
    {
        $filter_type = $this->grav['uri']->param('type');
        if (!$filter_type) {
            return $filesFiltered;
        }

        $filesFiltered = array_filter($filesFiltered, function ($file) use ($filter_type) {
            return $file['type'] == $filter_type;
        });

        return $filesFiltered;
    }

    /**
     * Filter media by date
     *
     * @param array $filesFiltered
     *
     * @return array
     */
    private function filterByDate($filesFiltered)
    {
        $filter_date = $this->grav['uri']->param('date');
        if (!$filter_date) {
            return $filesFiltered;
        }

        $year = substr($filter_date, 0, 4);
        $month = substr($filter_date, 5, 2);

        $filesFilteredByDate = [];

        foreach($filesFiltered as $file) {
            $filedate = $this->fileDate($file['file']);
            $fileYear = $filedate->format('Y');
            $fileMonth = $filedate->format('m');

            if ($fileYear == $year && $fileMonth == $month) {
                $filesFilteredByDate[] = $file;
            }
        }

        return $filesFilteredByDate;
    }

    /**
     * Return the DateTime object representation of a file modified date
     *
     * @param File $file
     *
     * @return DateTime
     */
    private function fileDate($file) {
        $datetime = new \DateTime();
        $datetime->setTimestamp($file->toArray()['modified']);
        return $datetime;
    }

    /**
     * Get the files dates list to be used in the Media Files filter
     *
     * @return array
     */
    public function filesDates()
    {
        $files = $this->files(false);
        $dates = [];

        foreach ($files as $file) {
            $datetime = $this->fileDate($file['file']);
            $year = $datetime->format('Y');
            $month = $datetime->format('m');

            if (!isset($dates[$year])) {
                $dates[$year] = [];
            }

            if (!isset($dates[$year][$month])) {
                $dates[$year][$month] = 1;
            } else {
                $dates[$year][$month]++;
            }
        }

        return $dates;
    }

    /**
     * Get the pages list to be used in the Media Files filter
     *
     * @return array
     */
    public function pages()
    {
        $pages = $this->grav['pages']->all();

        $pagesWithFiles = [];
        if ($pages) foreach ($pages as $page) {
            if (count($page->media()->all())) {
                $pagesWithFiles[] = $page;
            }
        }

        return $pagesWithFiles;
    }

    /**
     * Get an instance of the TwoFactorAuth object
     *
     * @return TwoFactorAuth
     */
    public function get2FA()
    {
        $provider = new BaconQRProvider();
        $twofa = new TwoFactorAuth('Grav', 6, 30, 'sha1', $provider);
        return $twofa;
    }

    /**
     * Get's an array of secret QRCode + chunked secret
     *
     * @param null $secret if not provided a new secret will be generated
     * @return bool
     */
    public function get2FAData($secret = null)
    {
        try {
            $user = clone($this->grav['user']);
            $twofa = $this->get2FA();

            // generate secret if needed
            if (!$secret) {
                $secret = $twofa->createSecret(160);
            }

            $label =  $user->username . ':' . $this->grav['config']->get('site.title');
            $image = $twofa->getQRCodeImageAsDataUri($label, $secret);

            $user->twofa_secret = str_replace(' ','',$secret);

            unset($user->authenticated);
            $user->save();

            $this->json_response = ['status' => 'success', 'image' => $image, 'secret' => trim(chunk_split($secret, 4, ' '))];
        } catch (\Exception $e) {
            $this->json_response = ['status' => 'error', 'message' => $e->getMessage()];
            return false;
        }
        return true;
    }

    public static function doAnyUsersExist()
    {
        // check for existence of a user account
        $account_dir = $file_path = Grav::instance()['locator']->findResource('account://');
        $user_check = glob($account_dir . '/*.yaml');

        if ($user_check != false && count((array)$user_check) > 0) {
            return true;
        }

        return false;
    }
}
